cohort replacement effect

I just read a Statistics Canada report stating that the gender wage gap has recently been decreasing. The report briefly noted that between 1988 and 2008, the wage gap narrowed throughout the wage distribution. However, the gap shrank the most at the lowest end of the wage distribution, and the gap shrank the least at the upper end. Also, although women dramatically increased their representation in high-wage occupations such as management, there were still significant gender wage gaps within these occupations.